<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
    .flex-container {
        display: flex;
        /*
        flex-wrap: wrap;
        justify-content: space-around;
        align-items: stretch;
        flex-direction: row;
         */
        width: 600px;
        height: 250px;
        background-color: lightgrey;
        
    }  
    .flex-item {
        background-color: cornflowerblue;
        /* width: 100px;
        height: 100px; */
        font-size: 50px;
        margin: 5px;
        color: white;
    }  
    .first{ order: -1}
    .last { order: 1} 

    .my1 { flex:1} 
    .my2 { flex:2} 
    .my3 { flex:1} 
    </style>
</head>
<body>
    <div class="flex-container">
        <div class="flex-item my1">1</div>
        <div class="flex-item my2">2</div>
        <div class="flex-item my3">3</div>
    </div>
</body>
</html>